Elastomeric polymers have a great variety of uses, e.g., in adhesives, electrical insulation, inks, sealants, paints, lacquers, varnishes and other coatings. In general, these polymers (hereinafter at times called "elastomers") have such versatility because they are two-phase or multi-phase substances in which one phase (typically called the "rubber" phase) contributes elasticity and another phase (normally more crystalline) provides tensile strength and dimensional stability. In many uses, these polymers are dissolved, emulsified or otherwise dispersed in a suitable liquid vehicle which facilitates their handling (e.g., for deposition on a solid surface) after which most or essentially all of the vehicle is removed, typically by evaporation, leaving the elastomer in position for the desired end use. This technique is widely practiced, but has significant disadvantages.
More specifically, most of such elastomers require the use of volatile organic (particularly aromatic vehicles to adequately dissolve their more crystalline phases at room temperature and concentrations of at least about 50% (in some cases at least about 30%). However, such vehicles can pose environmental pollution problems, worker inhalation dangers and/or explosion hazards. In addition, there are various costs that increase with the amount of vehicle employed, e.g. shipping expense, losses to the atmosphere, and equipment and procedures for vehicle recovery (in some cases with recycle).
In other, equally important elastomer applications the need for a vehicle is diminished or avoided by applying the elastomer in molten form, but this requires additional energy to melt the elastomer and can result in partial degradation of the polymer. The higher the temperature needed to melt the elastomer, the greater the energy requirement and degradation potential.
Usually, the problems of elastomer deposition can be at least partly overcome by the use of a relatively nonvolatile substance that renders the elastomer more tractable, i.e., a plasticizer, but this generally has the drawback of lessening the cohesion of the elastomer and thereby decreasing its strength in the intended end use. Thus the substances which tend to decrease the amount of organic vehicle and/or energy needed for deposition of the elastomer typically diminish the strength of the elastomer after evaporation of the solvent and/or resolidification of the elastomer. Minimizing this loss of strength is critically important for most uses of the elastomers, e.g. in adhesives, protective coatings, etc.
An object of this invention is a class of compounds having attractive utilities, particularly in providing attractive elastomer compositions. Another object is elastomer compositions containing such compounds, including elastomer compositions useful in satisfactory deposition or other handling of the elastomer, especially with little or no adverse effect on elastomer strength. Another object is elastomer compositions which can be solvent-, latex- or melt-deposited without requiring excessive energy for vehicle removal or melting of the elastomer. Other objects are to decrease pollution problems, explosion hazards and/or other personnel dangers from vehicle removal, the costs of transporting vehicle-containing elastomer compositions and/or ultimately the unit cost of articles containing the elastomer. Other objects include elastomer compositions having good adhesive properties, and a class of novel compounds useful in providing such compositions. These and other objects will be more readily understood from the following disclosure in which all parts and percentages are by weight and all temperatures are in degrees Celsius except as otherwise noted.